Vanesa RuizE-magy
Vanesa Ruiz
Materials Science PhD
https://e-magy.com/
About
61
Publications
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Introduction
Senior Battery Expert; Safety, Performance and Durability of Lithium ion Batteries
Additional affiliations
October 2013 - October 2022
Position
- Research Officer
Description
- Policy support in the areas of battery safety , performance and durability
September 2011 - October 2013
July 2008 - December 2010
Education
September 1999 - May 2003
Publications
Publications (61)
Research on battery materials is an ever-growing field that touches upon countless interests and applications; from improved anode and cathode compositions, to improved electrolytes and separators, not forgetting the long list of possible additives aiming at, for instance, developing a better and more stable solid–electrolyte interphase (SEI) layer...
This paper discussed possible criteria and measurement systems for the future Battery Sustainability Regulation.
Electrochemical impedance spectroscopy (EIS) is a widely applied non-destructive method of characterisation of Li-ion batteries. Despite its ease of application, there are inherent challenges in ensuring the quality and reproducibility of the measurement, as well as reliable interpretation and validation of impedance data. Here, we present a focus...
Differential Scanning Calorimetry (DSC) and Thermal Gravimetry (TGA) combined with gas analysis are used to identify the main decomposition processes and to develop reaction kinetic models for thermal runaway modelling of Graphite – Lithium Nickel–Manganese–Cobalt-Oxide (NMC 111) cells. Heating rates of 5, 10 and 15 °C min−1 with multiple replicati...
Internal short-circuit is one of the major safety hazards in lithium-ion battery systems, possibly leading to single cell thermal runaway (TR) and propagation to neighbouring cells. Therefore, developing tests to assess safety properties of batteries is essential to prevent potential safety hazards to the users. The main goal of this work is to und...
The Joint Research Centre (JRC) of the European Commission organised a workshop under the umbrella of its Exploratory Research Programme. The Workshop titled: 'Safer Li-ion batteries by preventing thermal propagation?' was held at the Directorate C-Energy, Transport and Climate in Petten on 8-9 March 2018. The workshop offered a platform where lead...
The effect of charging and discharging lithium iron phosphate-graphite cells at different temperatures on their degradation is evaluated systematically. The degradation of the cells is assessed by using 10 charging and discharging temperature permutations ranging from -20 °C to 30 °C. This allows an analysis of the effect of charge and discharge te...
BATTEST laboratory facilities for performance and safety evaluation of automotive Lithium ion batteries
Identifying factors which affect the ageing of Li-ion batteries is a major concern for various industries.
It is here reported, for the first time, an IR transparent side-by-side battery cell as a tool for the determination of local defects and the identification of failure mechanisms.
Lithium ion batteries are a proven technology for automotive applications and their continued use in the future electric vehicle fleet is undeniable. In addition to battery performance and durability, battery safety is paramount to ensure confidence and widespread adoption of electromobility in our society. This comprehensive review aims at present...
This study aims at analyzing the response of Li-ion cells and at identifying the hazards and governing phenomena from hard to soft external short circuit conditions. 10 Ah pouch cells and 4.5 mAh coin cells were short circuited while synchronized current, potential and temperature signals, audio, IR and visual video recordings were registered. The...
This work presents a systematic evaluation of the effect of dissimilar charging / discharging temperatures on the long-term performance of lithium iron phosphate / graphite based cells by using multi-factor analysis of variance. Specifically, the degradation of prototype pouch cells is presented in a range of charging and discharging temperatures f...
In this chapter the safety of rechargeable energy storage systems is discussed with a focus on Li-ion batteries. The main hazards, such as fire, explosion, direct electrical hazards (electrical shock and arcing), indirect electrical hazards, and chemical hazards are reviewed. Relevant failure scenarios—overheating, mechanical deformation, external...
In this paper, phosphomolybdic acid H3PMo12O40 (PMo12) was anchored to four synthetic micro-mesoporous carbons and a commercial one to analyse the relationship between the porous texture of the support, the PMo12 adsorption and the performance of the resulting hybrid materials as electrodes in supercapacitors. The uptake of PMo12 on carbon supports...
The present work reports the use and application of a novel protic ionic liquid (triethylammonium bis(trifluoromethylsulfonyl)imide; NEt3H TFSI) as an electrolyte for symmetric planar micro-supercapacitors based on silicon nanowire electrodes. The excellent performance of the device has been successfully demonstrated using cyclic voltammetry, galva...
The hybrid approach allows for a reinforcing combination of properties of dissimilar components in
synergic combinations. From hybrid materials to hybrid devices the approach offers opportunities to
tackle much needed improvements in the performance of energy storage devices. This paper reviews
the different approaches and scales of hybrids, materi...
Stable anchoring of polyoxometalate H3PMo12O40 onto in-situ Reduced Graphene Oxide leads to a hybrid electrode with combined capacitive (GO) and faradaic (H3PMo12O40) charge storage mechanisms featuring increased capacitance, energy density and extended cyclability.
The development of a novel hybrid symmetric micro-ultracapacitor based on poly(3,4-ethylenedioxythiophene) coated silicon nanowires using an ionic liquid (N-methyl-N-propylpyrrolidinium bis(trifluoromethylsulfonyl)imide) as an electrolyte has been demonstrated. The hybrid supercapacitor device was able to deliver a specific energy of 10 Wh kg-1 and...
The use of hybrid electrodes prepared from phosphotungstic acid (H3PW12O40, PW12) and activated carbon (AC) allows the fabrication of highly durable aqueous supercapacitors operating at a superior voltage (1.6 V) thanks to the high overpotential of PW12 towards H2 generation. The combination of the double-layer capacitance plus the redox activity o...
In order to understand the participation of electrical double layer and pseudocapacitance to the overall behavior of supercapacitors, a new approach to the analysis of the electrochemical data is proposed. Both the variation of the specific capacitance values and the dependence of these values with the operating voltage window (varying from 0–0.2 V...
The design and development of hybrid organic- inorganic materials with improved electrochemical performance to be used in energy storage applications (e.g. supercapacitors) has been investigated. The systematic study carried out shows carbon–based materials where the anchoring of inorganic species takes place (i.e. polyoxometalates, POM) in search...
Ionic liquid (IL)-based electrolytes containing molecular solvents were shown to be attractive for extreme temperature applications in electric double layer capacitors (EDLCs). In particular, the IL–butyronitrile (BuCN) mixture provides high capacitance (around 125 F g−1 at 500 mA g−1) independent of testing temperature, and superior performance at...
The hybrid approach allows for a reinforcing combination of properties of dissimilar components in synergic combinations. From hybrid materials to hybrid nanocomposite electrodes the approach offers opportunities to tackle much needed improvements in the performance of energy storage devices. This paper presents different types of hybrid materials...
Porous carbons with controllable and narrow pore-size distributions are prepared from the chemical activation of polyfurfuryl alcohol (PFA). High apparent BET surface areas, up to 2600 m2 g−1 (2611 m2 g−1 by Density Functional Theory (DFT)), and good electrical conductivities (up to ∼130 S cm−1) are obtained. By varying the potassium hydroxide: car...
The role played by carbon porosity and electrolyte chemistry in the development of double-layer supercapacitors based on solvent-free ionic liquids (ILs) of a wide electrochemical stability window is investigated. Voltammetric studies performed in N-methyl-N-butyl-pyrrolidinium bis(trifluoromethanesulfonyl)imide (PYR(14)TFSI), N-trimethyl-N-propyla...
A homologous series of ionic liquids (IL) with 1-alkyl-3-methylimidazolium cations of different lengths of alkyl chain was used to study the effect of cation size on the capacitive response of two carbons with a tailored pore size distribution. The results reveal a clear ion-sieving effect in pure ILs, while the effect is heavily mitigated for the...
The capacity to store energy in ultracapacitors or double-layer capacitors is about two orders of magnitude greater than that of ordinary capacitors. Also, their capability to receive and transfer power is greater than that of batteries in the same order of magnitude. These characteristics, together with their long life cycle ( $>$ 500 000) and the...
Polyfurfuryl alcohol (PFA) derived activated carbons were prepared by the acid catalysed polymerization of furfuryl alcohol, followed by potassium hydroxide activation. Activated carbons with apparent BET surface areas ranging from 1070 to 2600 m2 g−1, and corresponding average micropore sizes between 0.6 and 1.6 nm were obtained. The porosity of t...
This work describes the chemical activation of a coke using two different activating agents to investigate their behavior as electrodes in supercapacitors. A coke was chemically activated with two hydroxides (KOH and NaOH) under nitrogen flow, at a constant mass hydroxide/coke ratio of 2 and temperatures of 600, 650, and 700 °C. All of the samples...
A pyrolysis product derived from a coal-tar pitch was chemically activated using KOH in a KOH/carbon proportion of 5:1. The activated carbon was used as electrode-active material for capacitive deionization (CDI). Electrochemical parameters, such as current values, charge, specific charge and charge−discharge efficiencies were investigated using a...
The behaviour of mesophase-derived electrodes on long-duration cycling conditions was studied in 1M sulfuric acid and 6M potassium hydroxide. Variation in the specific capacitance values with the number of cycles shows a good cycling life performance in acidic media but very poor in an alkaline electrolyte. The total loss of capacitance after 7000...
6 pages, 6 figures, 1 table.-- Available online Oct 2, 2008. Activated carbon binderless monoliths with high consistency and large porosity, synthesised from a mesophase pitch, are studied as electrodes for supercapacitors. The electrochemical cells prepared provided high capacitance values in sulphuric acid media (334 F g−1) and very low electrica...
6 pages, 6 figures.-- Printed version published Dec 30, 2008. This paper studies the effect of thermal treatment on the long-term performance of carbon-based supercapacitors. Two active electrode materials were studied: a mesophase derived activated carbon (AC), rich in oxygen functionalities, and an activated carbon obtained from treating AC at 10...
The electrochemical behaviour of a chemically activated carbon with oxygen-containing surface groups was studied using a conventional macroelectrode configuration with disc electrodes and the single particle microelectrode technique. The results of both experimental set-ups were compare taking into account the visible peaks of the surface groups, c...
7 pages, 7 figures, 3 tables.-- Printed version published Jul 1, 2008. This paper reports on the electrochemical performance of carbon-based electrodes subjected to thermal treatment. Changes in texture and chemical composition were evaluated and used to assess the effect of thermal treatment on the electrochemical performance of the resultant supe...
5 pages, 4 figures, 1 table. -- Available online 27 June 2007. Various microporous carbon molecular sieves are studied as active electrode material for supercapacitors in order to clarify the controversy about the accessibility of the electrolyte to the micropores. Cyclic voltammetry experiments were performed in electrolytes with different ion siz...
Cyclic voltammetry was performed on activated carbon particles in a microelectrode setup to investigate the behaviour of an activated carbon with oxygen functionalities. Quinoid type redox peaks were clearly seen in the potential region around −0.5 V vs. Hg/HgO. After polarization below −0.4 V, an anodic peak confirms previous studies using a prist...
This work investigates the influence of electrode preparation on the electrochemical behaviour of carbon-based supercapacitors.
Studies were performed using the same activated carbon and polymer polyvynilidene fluoride (PVDF) in the same proportions
(10 wt.% PVDF). Only the way in which these components were mixed was modified. The procedure for mi...
This paper studies the electrochemical behaviour of activated carbons with different oxygen content and investigates the contribution of pseudocapacitance to the global behaviour of the samples. A mesophase-derived activated carbon was further heat treated to 600 or 1000 °C in nitrogen. The changes in texture and surface chemistry induced by the th...
Mesophase pitch AR24 was directly activated with KOH using different proportions of the activating agent and activation temperatures, to study the effect on the textural characteristics of the resultant activated carbons and how these characteristics influence their behaviour as electrodes in supercapacitors. The textural properties of the activate...
A pyrolysis product derived from Sasol-Lurgi gasifier pitch was activated using different proportions of KOH. The increase of the amount of KOH used for activation caused the activation degree of the carbons to increase very significantly. The activated carbons obtained using lower amounts of KOH were mainly microporous, while the amount of mesopor...
Introduction Commercially available electric double layer capacitors (EDLCs) having symmetrical high-surface area activated carbon (AC) electrodes are promising energy storage devices. They are capable of delivering high power in short periods of time for use in a variety of applications from digital electronics to electric vehicles. However, a lim...
Questions
Questions (3)
Our Health & Safety team on site is trying to convince us to work with the Glove Box in under pressure. Our normal work is Li ion battery assembly in 2 and 3 electrode configurations with metallic lithium used regularly and with standard organic battery electrolyte. How can I convince them that working in over pressure is a standard procedure in this type of activity?. Thanks!
need to know if the results from a TriStar 3000 can be exported / saved into txt. or ascii? so they can be plotted into a graph using excell, origin...
and are the original files compatible with ASAP application?
Very useful website where many graphene companies can be found.
